JPH0383966A - Production of aromatic carboxylic acid having sulfonyl group - Google Patents

Abstract

PURPOSE:To obtain the subject compound for a raw material of a polymer excellent in heat resistance and moldability at a high selectivity and in a high yield by carrying out liquid phase oxidation of a specified aromatic compound using molecular oxygen in the presence of a Co-Mn-Br-based catalyst in a prescribed ratio based on the solvent. CONSTITUTION:In oxidation of an aromatic compound [e.g. bis[4-(4- methylphenylsulfonyl)phenyl]ether] represented by the formula (R1 and R2 are H or lower alkyl; (n) is integer of 0-4 in case R1 and R2 are not H) by molecular oxygen in a fatty carboxylic acid solvent, a Co-Mn-Br-based catalyst composed of a Co compound of 0.10-0.17 pts.wt. calculated as Co metal, an Mn compound of 0.0007-0.0018 pts.wt. calculated as Mn metal and a Br compound of >=0.0465 pts.wt. calculated as Br atom based on 100 pts.wt. solvent is used as a catalyst, thus efficiently producing the subject compound of high purity, i.e., at a high selectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for producing an aromatic carboxylic acid having a sulfonyl group, and more specifically, it is used in producing useful polymers such as polyester, polyamide, or polyimide. , relates to a method for producing an aromatic carboxylic acid having a sulfonyl group.

Technical Background of the Invention Many aromatic compounds having functional groups such as carboxyl groups and imide groups are known as raw materials for heat-resistant polymers.

For example, pyromellitic acid (anhydride) is used as a raw material for polyimide such as Kapton ■, or
Aromatic bis(ether acid anhydride) and the like are known as raw materials for polyetherimide as disclosed in Japanese Patent No. 24242.

However, polyimide obtained using pyromellitic acid (anhydride) as a raw material has excellent heat resistance but poor moldability, and polyetherimide obtained using aromatic bis(ether acid anhydride) as a raw material has poor heat resistance. There was a problem.

For this reason, there has been a desire for the emergence of a new aromatic carboxylic acid that can be used as a raw material for polyimide that has an excellent balance between heat resistance and moldability.

On the other hand, polyester, whose main chains are linked by ester bonds through polycondensation of dibasic acid and dihydric alcohol, is widely used as a polymer material for synthetic fibers and films. . Furthermore, it is well known that polyamides useful as polymeric materials for synthetic fibers can be produced from dibasic acids and diamines.

In this way, dibasic acids are extremely useful compounds as starting materials when producing polyesters or polyamides, etc. However, dibasic acids as raw materials for polymers such as those mentioned above are used in the oxidation reaction of p-xylene. Terephthalic acid obtained by oxidation of m-xylene or isophthalic acid obtained by oxidation of m-xylene is widely known.

However, the technology for producing polymers such as polyester or polyamide using terephthalic acid or isophthalic acid as a starting material has been thoroughly researched in a sense.
It has been pointed out that the resulting polymers have problems, such as poor heat resistance or processability.

For this reason, there is a desire for the emergence of new aromatic carboxylic acids that can be used as raw materials for completely new polyesters or polyamides.

In view of such prior art, for example, Japanese Patent Application Laid-Open No. 63-8
No. 3653 discloses that sulfonyl group-containing aromatic compounds represented by the following general formula [II] are subjected to liquid phase oxidation with molecular oxygen in the presence of a cobalt-manganese-bromine catalyst. A method for producing aromatic carboxylic acids having groups is disclosed.

(In the formula, R and R5 may each be the same or different and represent hydrogen or a carboxyl group, and R and R7 may each be the same or different and represent hydrogen, a lower alkyl group or a carboxyl group. and
n is the number of substituents other than hydrogen, and is an integer of 0 to 4. ) The present inventors further investigated in light of the above-mentioned prior art, and found that when a specific aromatic compound is subjected to liquid phase oxidation with molecular oxygen, specific amounts of cobalt compounds, manganese compounds, and bromine compounds are combined. The inventors have now completed the present invention by discovering that aromatic carboxylic acids having sulfonyl groups can be efficiently produced with high purity, ie, high selectivity, by using a specific amount of sulfonyl group-containing aromatic carboxylic acids.

Purpose of the Invention The present invention was completed in view of the above-mentioned points, and is a method for producing highly aromatic carboxylic acids containing sulfonyl groups, which are useful for producing polymers such as polyesters, polyamides, and polyimides. It is an object of the present invention to provide a method for producing an aromatic carboxylic acid containing a sulfonyl group, which can be produced by a general reaction with high selectivity and high yield.

Summary of the Invention The method for producing an aromatic carboxylic acid according to the present invention is to prepare a compound represented by the following general formula [I] in a molecular form in an aliphatic carboxylic acid solvent in the presence of a cobalt-manganese-bromine catalyst. When carrying out liquid phase oxidation with oxygen, 0.0% cobalt compound is added as cobalt metal to 100 parts by weight of solvent.
The manganese compound is used in an amount of 0.0007 to 0.0018 parts by weight as manganese metal, and the bromine compound is used as a bromine atom in an amount of at least 0.0007 to 0.0018 parts by weight.
It is characterized in that it is used in an amount of 0,465 parts by weight or more.

[In the formula, R and R2 are each the same and may be different, and are hydrogen or a lower alkyl group, and n is the number of substituents other than hydrogen, and is an integer of 0 to 4. According to the present invention, a compound represented by the above general formula [I] is reacted with molecular oxygen in the presence of a specific amount of a cobalt-manganese-bromine catalyst in an aliphatic carboxylic acid solvent. By liquid phase oxidation, the aromatic carboxylic acid represented by the following general formula [n] can be efficiently produced with high purity.

... [II] (wherein R and R7 may be the same or different, and are hydrogen, a lower alkyl group, or a carboxyl group, and n is the number of substituents other than hydrogen, 0～
It is an integer of 4. ) Detailed Description of the Invention The method for producing an aromatic carboxylic acid having a sulfonyl group according to the present invention will be specifically described below.

The aromatic compound used as a raw material has the following general formula [1]% formula% [] (wherein R and R are each the same and may be different, are hydrogen or a lower alkyl group, and n is the number of substituents other than hydrogen, and is an integer of O to 4.) The aromatic compound represented by the above general formula [I] can be produced, for example, as follows.

That is, a pt-luenesulfonyl chloride represented by the following general formula [m] and a diphenyl ether represented by the following general formula [IV] are reacted, for example, in the presence of a Lewis acid such as aluminum trichloride. By this, an aromatic compound represented by the above general formula [1] can be obtained.

[III] [IV] [I] In the present invention, the aromatic compound represented by the general formula [I] is
In an aliphatic carboxylic acid solvent, in the presence of a specific amount of a cobalt-manganese-bromine catalyst, the aromatic carboxylic acid represented by the general formula [・■] is oxidized in a liquid phase using molecular oxygen, such as air. Manufactured.

As the aliphatic carboxylic acid used as the reaction solvent, acetic acid, flopionic acid, butyric acid, valeric acid, etc. are used, and among these, acetic acid is particularly preferred. Such aliphatic carboxylic acids may contain a small amount of water, and in some cases, organic solvents such as aldehydes, ketones, and alcohols may be mixed with the aliphatic carboxylic acids.

It is usually preferable to use such a solvent in an amount of 5 to 50 iR parts per 1 part by weight of the aromatic compound as a reaction raw material.

As a catalyst for the above reaction, a cobalt-manganese-bromine catalyst is used. Cobalt and manganese are usually used as metal salts soluble in the reaction solvent, such as inorganic salts, acetates, naphthenates, etc., but specifically, cobalt acetate, cobalt bromide, cobalt naphthenate,
It is used as manganese acetate, manganese bromide, manganese naphthenate, etc. In addition, bromine is added to the reaction system by hydrogen bromide,
As inorganic bromine compounds such as sodium bromide and potassium bromide or organic bromine compounds such as tetrabromoethane,
Alternatively, it is added in the form of cobalt bromide, manganese bromide, etc.

The cobalt compound is used in an amount of 0.10 to 0.17 parts by weight as cobalt metal per 100 parts by weight of solvent, and the manganese compound is added in an amount of 0.0007 to 0.0018 parts by weight as manganese metal per 100 parts by weight of solvent. Preferably, it is used in an amount of 1 part. In addition, the bromine compound is at least 0.0 bromine atom per 10 parts by weight of the solvent.
It is preferably used in an amount of 465 parts by weight or more, preferably 0.0465 to 2.8 parts by weight.

Using such specific amounts of a cobalt compound, a manganese compound, and a bromine compound as catalysts, the formula [N
When the aromatic compound represented by the formula [1] is oxidized, the aromatic compound represented by the formula [1
The aromatic carboxylic acid compound shown in [1] can be produced with high purity in one step.

When the aromatic compound represented by the general formula [I] is oxidized using a cobalt compound, a manganese compound, and a bromine compound in amounts outside the above range, the aromatic compound represented by the general formula [1] It becomes difficult to obtain carboxylic acid compounds with high selectivity and high yield. This is because the aromatic compound represented by the general formula [I] has a sulfonyl group, ether bonds, and numerous aromatic nuclei in the molecule, and it is possible to selectively oxidize the aromatic side chain methyl group. This is probably because it is difficult.

In the oxidation reaction, molecular oxygen is used as an oxygen source, and pure oxygen or air is used as the molecular oxygen.

The reaction temperature is 50-350°C, preferably 180-220°C.
It is desirable that the temperature is ℃. The reaction can be carried out under normal pressure or at 30°C.
It can be carried out under any conditions under pressure up to about atmospheric pressure. The reaction is preferably carried out in a liquid phase, and when the reaction is carried out at a temperature higher than the boiling point of the solvent, it is preferably carried out under pressure.

Aromatic carboxylic acid, which is a reaction product, can be produced by, for example, cooling the reaction mixture, adding water to the reaction mixture, dissolving the precipitated solid in an alkaline aqueous solution, and then making the solution acidic to precipitate the solid. You can get it.

The obtained reaction product was analyzed by H-NMR analysis, IR analysis,
The structure is determined by elemental analysis, etc., and it is confirmed that it is an aromatic carboxylic acid as shown by the general formula [11].

Effects of the Invention According to the present invention, a compound represented by the general formula [I] is liquefied with molecular oxygen in an aliphatic carboxylic acid solvent in the presence of a specific amount of a cobalt-manganese-bromine catalyst. By phase oxidation, the aromatic carboxylic acid represented by the general formula [II] can be produced with high purity, that is, with high selectivity, and economically by a one-step reaction.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Reflux cooling device, stirring device, heating device and raw material inlet,
800 g of acetic acid and bis[4-(4-method) were placed in a titanium pressure-resistant reactor having a gas inlet and a reactant outlet.

Tylphenylsulfonyl)phenyl]ether 80g1
Cobalt acetate 3.922g, manganese acetate 0.0357
After charging 0.802 g of hydrobromic acid and pressurizing nitrogen from the gas inlet to bring the pressure to 15 kg/c-,
The temperature was raised to 90°C. When the temperature reached 190°C, air was introduced and the reaction was carried out for 90 minutes.

After the reaction was completed, the reaction mixture was taken out from the reactor, and the solvent was distilled off under reduced pressure. Next, add a small amount of 5 to the distillation residue.
% aqueous hydrochloric acid solution was added and heated while stirring, and then left to stand day and night.

When this solid was separated into solid and liquid and dried under reduced pressure, 111
．． 1 g of white crystals was obtained. This is about 1 for the crystal.
Recrystallization was performed once with 0 times the amount of acetone.

The obtained crystals were analyzed by liquid chromatography to identify the target substance, 4,4°-bis(3,4-dicarboxyphenylsulfonyl)diphenyl ether (
BO2 [;) and other impurities (reaction intermediates and reaction by-products) were quantified.

In addition, as a method for evaluating the color of the product, a portion of the crystal was dissolved in isooctane and the visible absorption spectrum at 280 nm was measured to determine the molecular extinction coefficient.

The lower the value of the molecular extinction coefficient, the better the color, and the higher the value, the better the color.

Note that the measurement conditions for liquid chromatography are as follows.

Column: TSK-ODS-80 gel manufactured by Toyo Soda 4.
6 mm x 15 cm Solution M: 10.05 mol of methanol, phosphate-potassium (pH 4,00) ratio 70/30 Flow rate: 0.6 ml/min Detector: UV 245 nm The analysis results of the obtained product are as follows. there were.

Purity: 99.0% Total impurities: 1.0% Molecular extinction coefficient: 0°001 Examples 2 to 7 Using the same equipment as in Example 1, the amounts of cobalt, manganese, and bromine components used were as shown in Table 1. Instead of
The reaction was carried out in the same manner as in Example 1.

The results obtained are shown in Table 1.

Note that Table 1 also shows the results of Example 1.

In Table 1, the amounts of cobalt, manganese, and bromine indicate parts by weight of cobalt metal, manganese metal, and bromine atom, respectively, based on 100 parts by weight of the solvent.

Comparative Examples 1 to 6 Using the same equipment as in Example 1, cobalt, manganese, and bromine components were concentrated in a range other than Examples 1 to 7 (all parts by weight based on 100 parts by weight of the solvent), focusing on one component. The reaction was carried out.

The obtained results are summarized in Table 2.

Claims (1)

[Claims] 1) When a compound represented by the following formula [I] is subjected to liquid phase oxidation with molecular oxygen in an aliphatic carboxylic acid solvent in the presence of a cobalt-manganese-bromine catalyst, the solvent With respect to 100 parts by weight, the cobalt compound is used in an amount of 0.10 to 0.17 parts by weight as cobalt metal, and the manganese compound is used in an amount of 0.0007 to 0.001 as manganese metal.
A method for producing an aromatic carboxylic acid having a sulfonyl group, which is used in an amount of 8 parts by weight, and a bromine compound is used in an amount of at least 0.0465 parts by weight as a bromine atom: ▲ Numerical formula, chemical formula, table, etc. There is a ).